So you tell me its a limitation of physics (essentially saying its impossible), then go on to say countless other institutions have been trying to do it for the last 10 years?
I never said it was impossible. I said it
is possible, but with current technology it uses too much power and has other problems as I stated. Scientists have been trying for years to get increased wireless power efficiency, and you think Apple (with very few scientists) has suddenly managed to crack it?
Have you ever seen Ted Talks? I remember seeing one about TRUE wireless charging - called it Witricity. Obviously there are issues currently....that's what technological advancement is all about. Do you think society 50 years ago would've thought it possible to fit a computer in the palm of your hand?
Witricity is a company, their tech uses inductive charging and has exactly the problems I have stated. Inductive charging is "true" charging, so not sure what you mean there, it's just very inefficient.
Technology is the tool used to make the "impossible", possible. In however many years, we'll be wirelessly charging our devices through our wifi connections and will wonder about the next advancement.
I don't doubt, but right now the tech isn't there yet. If the watch was sat on a charging pad you get fairly good efficiency, but certainly not at one meter. The amount of power required (and the size of the antenna) increase exponentially as the distance from the antenna increases. The magnetic field decreases at a rate of distance^-3.
RFID uses the same tech, and the maximum read range with a transmission coil of 10cm and receiving coil of 3cm is around 15cm. Those tags require just 1v and 1 microamp, thats 0.000001 amps. For comparison, the iPhone uses 1 amp at 5 volts.
Another issue is the watch couldn't be metal, or have any large metal objects inside, since they would shield and completely de-tune both the receiving and transmission antenna. Hell, anything metallic within a 1 meter radius of the transmission antenna would detune it and reduce its range.
And ya - Apple with its $150 billion in cash and vast resources across the globe could certainly have accomplished something like this. Not all that surprising.
But where are their scientists? You don't just employ thousands of scientists without anyone knowing, especially since Apple's workforce is comparatively small (13k-ish), iirc.
I think you are exaggerating a bit for effect, but I agree in principle.
The real issue is not the size of the transmitter, but the inefficiency of the process. How green can you be when you are building an RF transmitter to transmit power like this over a meter sphere? The power reduction is a function of the radius cubed (unless you are dealing with directed antennas at very high frequencies, which can cook birds out of the sky)... Seems kind of un-Apple like.
All those people complaining about "vampire losses" from wall worts plugged in all over the place will finally have a new cause to champion, because this thing will not be efficient.
I completely agree, non-targetted RF is terribly inefficient.
Tesla worked on this for decades, along with beamed energy weapons (kind of the same thing), starting in the early 1900's. Notice we still have high power transmission lines all over the place.
Note: recent MIT experimentation with resonance to allow efficient transfer of power is interesting, and possibly what we are talking about here. This is interesting, because Tesla was also convinced that resonance was the key to long term power transmission, and was trying to find the resonance frequency of the entire earth. Commonly known as "Tesla's Folly".
http://phys.org/news100445957.html
http://www.pbs.org/tesla/ll/ll_todre.html
That is interesting, thanks! RFID tags use the resonant frequency to get optimal range.
"which will allow the device to charge from up to a meter away"
What kind of sorcery is this?
Haha, exactly!
Edit: notice the half meter coils on the receiving and transmitting side at the MIT!
